The renin-angiotensin system plays a well-defined role in cardiovascular homeostasis. Renin is an aspartic protease which converts angiotensinogen to Angiotensin I, which is acted upon by angiotensin converting enzyme (ACE) to form the vasoactive octapeptide, Angiotensin II. It is now well-known that inhibitors of renin will serve as antihypertensives in mammals. Since HIV protease is in the aspartyl protease class of enzymes (like renin), it is believed that inhibitors of renin will also be effective in the direct or adjunctive treatment of AIDS and other viral diseases.